2018 Pollution Report to the LegislatureThis report is available in alternative formats upon request, and online at . Document number: lrp-ear-2sy18 Legislative charge Minn. Statutes

April 2018

2018 Pollution Report to the Legislature

Pollution

Minnesota Pollution Control Agency

520 Lafayette Road North | Saint Paul, MN 55155-4194 |

651-296-6300 | 800-657-3864 | Or use your preferred relay service. | [email protected]

This report is available in alternative formats upon request, and online at www.pca.state.mn.us.

Document number: lrp-ear-2sy18

Legislative charge Minn. Statutes § 116.011 Pollution Report

A goal of the Pollution Control Agency is to reduce the amount of pollution that is emitted in the state. By April 1 of each even-numbered year, the Pollution Control Agency shall report the best estimate of the agency of the total volume of water and air pollution that was emitted in the state in the previous two calendar years for which data are available. The agency shall report its findings for both water and air pollution:

(1) in gross amounts, including the percentage increase or decrease over the previously reported two calendar years; and

(2) in a manner which will demonstrate the magnitude of the various sources of water and air pollution.

History:

1995 c 247 art 1 s 36; 2001 c 187 s 3; 2012 c 272 s 72

Authors

Patricia Engelking

Azra Kovacevic

Contributors/acknowledgements The report was prepared with assistance from other staff in the MPCA’s Municipal, Industrial, Operations, Watershed, and Environmental Analysis and Outcomes divisions. Special thanks to Anne Claflin, Mark Ferrey, Theresa Gaffey, Marco Graziani, Paul Hoff, Tanja Michels, Bruce Monson, Barb Olafson, Kari Palmer, Rebecca Place, Casey Scott, and Summer Streets.

Estimated cost of

preparing this report (as

required by Minn. Stat. §

3.197)

Total staff time: 187 hrs.

$11,228.00

Production/duplication $110.00

Total $11,338.00

The MPCA is reducing printing and mailing costs

by using the Internet to distribute reports and

information to wider audience. Visit our

website for more information.

MPCA reports are printed on 100% post-

consumer recycled content paper

manufactured without chlorine or chlorine

derivatives.

On the cover: Cars, trucks and other mobile sources continue to be a major source of air pollutant emissions, including greenhouse gases, in urban areas across Minnesota. Deicing salt needed for safe traffic flow in Minnesota winters is a cause of chloride-impaired streams, prompting advances in “smart salting” by state and local government snowplow drivers.

mailto:[email protected]

http://www.pca.state.mn.us/

i

Contents Executive summary .................................................................................................................................. 1

Air emissions .................................................................................................................................................... 1

Water discharges .............................................................................................................................................. 4

Air pollutant emissions overview .............................................................................................................. 7

Criteria air pollutant emissions ........................................................................................................................ 8

Air toxics ......................................................................................................................................................... 11

Greenhouse gases .......................................................................................................................................... 12

Mercury .......................................................................................................................................................... 13

Water pollutant discharges overview ...................................................................................................... 17

Wastewater discharges .................................................................................................................................. 17

Nonpoint source pollution ............................................................................................................................. 35

Contaminants of emerging concern ............................................................................................................... 38

2018 Pollution Report to the Legislature • April 2018 Minnesota Pollution Control Agency

1

Executive summary Every two years, the Minnesota Pollution Control Agency (MPCA) uses the most recent data available to

estimate the total amounts of pollution emitted into our air and discharged to our water resources. The

MPCA also estimates the percentage increase or decrease over the previous two calendar years, and the

relative contributions of the various sources of pollution.

This report also includes information on emissions of toxic air pollutants, greenhouse gas emissions,

nonpoint source water pollutants, and emerging contaminants of concern. While it is still not possible to

quantify the amounts of all of these pollutants released in the environment, the agency is working to

understand the effects of these pollutants on human health and the environment and to develop

strategies to reduce their presence in Minnesota’s air and water.

Air emissions

In this report, the MPCA details statewide emissions of pollutants to Minnesota’s air, including criteria

air pollutants (pollutants with national ambient air quality standards), greenhouse gases, and other air

toxics.

Emissions from larger facilities are available every year; however, emissions from other sources are only

available every three years. It is important to note that the 2014 data presented in this report are draft

and once finalized emissions become available they may differ significantly from current estimates.

Initial estimates are recalculated based on federal economic data and other factors influencing emission

sources.

Figure 1 provides estimated total statewide emissions of four major criteria air pollutants from 2002 to

2016. During this time, estimated emissions of these pollutants have been reduced by almost 50%.

While this report is focused on statewide total emissions, MPCA understands that some air pollutants

are emitted disproportionately in areas of concern.


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Emissions in 2002, 2005, 2008, 2011 and 2014 are from all sources, including mobile, non-permitted and permitted sources. Subsequent yearly emissions changes are due entirely to permitted sources. Mobile and non-permitted estimates were held constant for in-between years. Prior to 2012, PM2.5 emissions were calculated every three years. In 2012, MPCA started calculating emissions annually for all permitted sources. It is therefore important not to place undue emphasis on yearly changes. Fire and biogenic emissions are not included in the totals because they vary greatly from year to year.

Since 2002, overall emissions have been decreasing. This is generally due to improvements in pollution

control technology, governmental regulations, and changes to estimation methodologies. Most criteria

pollutant emission estimates from permitted sources decreased between 2014 and 2016. Changes at

utilities and mining companies resulted in major decreases in sulfur dioxide and nitrogen oxide

emissions. Mining production was down in 2016 compared to both 2014 and 2015, resulting in lower

emissions. In 2015, Xcel Energy – Black Dog Plant switched from burning coal to natural gas, and Xcel

Energy – Sherburne Generating Plant installed new control equipment, which decreased emissions

significantly. Minnesota Power – Bowell Energy Center also burned less coal than in 2014.

In 2016, all facility criteria emissions continued to decrease except for ammonia. Ammonia emissions

increased slightly from 2015. This increase in likely due to the inclusion of new and updated emission

factors for combustion processes. Statewide draft emission estimates for 2014 across all sources have

decreased in comparison to 2011. The states and the U.S. Environmental Protection Agency (EPA) have

taken steps to increase transparency and collaboration among the different state and federal

organizations. As a result, for the 2014 emission inventory, a number of methodological improvements

were implemented for many categories including solvent use and industrial/commercial/institutional

combustion.

In 2014, most air pollution came from smaller, widespread sources, including vehicles, small businesses

and construction equipment. Figure 2 shows a breakdown of draft 2014 statewide emissions.

500,000

600,000

700,000

800,000

900,000

1,000,000

1,100,000

1,200,000

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Emis

sio

ns

(To

ns)

Year

Aggregate emissions NOX, SO2, VOC, PM2.5

Figure 1. Minnesota statewide emissions trends


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Figure 2. Sources of criteria air pollutant emissions in Minnesota, 2014

A third of Minnesota emissions come from non-permitted sources, such as auto-body shops, gas

stations, and home heating and air conditioning systems. Individually, these are small sources, but when

combined, contribute significantly to overall emissions. On-road vehicles, such as cars and trucks, make

up about 23% of emissions in Minnesota. Off-road vehicles and agricultural and construction equipment

contribute 22% of total emissions in Minnesota. Emissions from permitted sources, typically power

plants and large industrial factories, make up about a quarter of total statewide emissions.

Lead, mercury and other air toxics are pollutants that can be toxic at very low concentrations. In 2014,

an estimated 17 tons of lead and more than 2000 (draft number) pounds of mercury were emitted in

Minnesota. These pollutants have also trended downward, with about 12% statewide decrease in air

emissions of lead from 2011 to 2014 with a 16% decrease in mercury during the same period.

In Minnesota, the MPCA estimates greenhouse gases (GHGs) for electric generation, transportation,

agriculture, industrial, residential, commercial, and waste sectors. The most recently completed

emission inventory for GHGs was in 2014. Since 2005, Minnesota’s total greenhouse gas emissions have

declined by about 4% and are currently not on track to meet the goals of the Next Generation Energy

Act. Air toxics are estimated every three years, with latest draft estimates available from 2014.

Statewide emissions have decreased for all source types compared to 2011 emissions.

There may be differences in the total emission figures for a given year discussed in this report versus

past MPCA emission reports because data may be updated in MPCA’s emission inventory due to

corrections or changes in methodology. Detailed and updated air emissions data can be found at

https://www.pca.state.mn.us/2018-pollution-report.

https://www.pca.state.mn.us/2018-pollution-report


4

Future emissions of pollution to Minnesota’s air may be influenced by a number of factors, including:

Emissions from electric utilities should continue to decrease due to increases in renewable energy sources such as wind and solar, increased energy efficiency, power plant modernization that includes retirement of less efficient, older coal plants, and increased use of natural gas.

Emissions from taconite facilities are expected to decrease due to future installation of NOx controls under federal rules and improved measurement methods.

Continued decreases in on-road mobile emissions due to more stringent federal vehicle tailpipe standards as fleets turn over both in light duty and heavy-duty vehicles.

Water discharges

In this report, the MPCA provides estimates of surface water discharges from point sources of pollution

—primarily municipal and industrial wastewater treatment facilities. The report also describes agency

efforts to reduce nonpoint sources of pollution and progress in watershed monitoring and assessment. A

final section highlights ongoing efforts in the state to monitor and address contaminants of emerging

concern.

Overall pollutant loads to receiving waters are based on a combination of effluent flow and pollutant

concentrations in the effluent. Loads are calculated by combining facility-reported flow and

concentration data. If facility-specific data are not available, loads are estimated with information based

on facilities with similar waste streams or other best professional judgment. Pollutant loads calculated

from measured wastewater flows and observed concentrations are considered to be highly reliable

while less confidence is warranted for pollutant loads derived from estimated concentrations.

The chart below shows pollutant effluent flow and loading trends for four measures of wastewater

pollution from 2000-2017. The four pollutants are total suspended solids (TSS), carbonaceous

biochemical oxygen demand (CBOD5), total phosphorus, and total nitrogen. Effluent flow is reported in

billion gallons per year. Pollutant loads for TSS, CBOD5, total phosphorus, and total nitrogen are

reported in metric tons per year.


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Overall, effluent flows tend to fluctuate based on precipitation. The overall health of the economy also

affects the amount of industrial production, which in turn affects industrial effluent flows and the

amount of industrial effluent treated at municipal wastewater treatment facilities. Regulatory policies

implemented over the past 15 years have promoted reduction of total phosphorus discharged by

wastewater treatment facilities, which has led to significant improvements in water quality. Total

phosphorus is the primary pollutant associated with increased algae growth in Minnesota’s lakes and

streams.

With the exception of total nitrogen levels, which have increased in wastewater discharges, facilities

have also decreased:

Total suspended solids, which are sediment and other particles that cloud the water.

Carbonaceous biochemical oxygen demand, which is a measurement of how pollutants can deplete oxygen needed by fish and other aquatic life.

Facilities throughout Minnesota have made significant investments in technology, equipment and

training that have led to these improvements.

Wastewater treatment facilities have also significantly reduced direct discharges of mercury to

Minnesota’s waters. Mercury is a toxic element that accumulates in fish tissue. Mercury reduction in

wastewater is a result of successful source reduction programs and installation of treatment

technologies for mercury removal, where necessary. On average, the data show a 42% reduction in

mercury loads from a 3.86 kilogram per year baseline in 2005/2006. Direct discharges of mercury in

wastewater are very small compared to atmospheric sources of pollution.

Minnesota has made significant progress in cleaning up point sources of water pollution but it is the

nonpoint sources of pollution from rainfall or snowmelt moving over or through the ground carrying

natural or human-made pollutants into lakes, streams or wetlands that now pose the greater challenge

for prevention and cleanup. Many of the stresses from nonpoint sources of pollution that affect

Minnesota’s surface and groundwater resources are the result of choices that people make every day

such as lawn care practices, farming practices, watercraft operation and waste disposal. The daily

decisions that homeowners, developers, farmers and businesses make regarding land uses are crucial to

protecting water resources from the effects of nonpoint source pollution.

Figure 3. Pollutant loading trends from Minnesota wastewater facilities, 2000-2017


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Point sources have the greatest potential to impact the environment during periods of low precipitation

and stream flow. Nonpoint sources include runoff from agricultural fields, feedlots, urban areas, and on-

site sewage treatment (septic) systems. Nonpoint sources are most significant during periods of high

precipitation and medium to high stream flow. Further improvements are needed in both point sources

and nonpoint sources of pollution in order to achieve goals set in federal and state law for protecting

human health and the environment.

Although there is no completely reliable way to quantify volumes of water pollutants released by

nonpoint sources, the Board of Water and Soil Resources (BWSR) tracks Clean Water Fund projects and

estimates pollutant reductions associated with them. From 2000 to 2017, more than 6,872 best

management conservation practices have been installed, resulting in a reduction of about 116,675

pounds of phosphorus and 121,394 tons of sediment across the state.

Future discharges of point source and nonpoint sources of pollution to Minnesota’s waters will be

influenced by a number of factors, including:

Wastewater treatment infrastructure — Minnesota’s wastewater systems are aging. Significant investments will be needed to replace failing infrastructure and upgrade treatment facilities to meet higher standards and expand systems to accommodate growth. Both rural and metro facilities face serious challenges to make these improvements to their infrastructure.

Nutrient Reduction Strategy — Multiple state and federal agencies developed the Minnesota Nutrient Reduction Strategy in 2014 to address excess levels of nutrients — primarily phosphorus and nitrogen — in Minnesota’s waters. Reduction goals for phosphorus and nitrogen outlined in the strategy are designed to protect both Minnesota waters and downstream waters, including both Lake Winnipeg and the Gulf of Mexico. Nitrate loads leaving Minnesota via the Mississippi River contribute to the oxygen-depleted “dead zone” in the Gulf of Mexico. A 2013 study, Nitrogen in Minnesota Surface Waters, indicated that more than 70% of nitrate is coming from cropland, with the rest coming from sources such as wastewater treatment plants, septic and urban runoff, forests and the atmosphere.

River eutrophication standards — First adopted in 2014, these standards are designed to protect aquatic life from the negative impacts of excess algae in rivers and streams. More restrictive limits associated with these standards have the potential to further reduce pollutants from wastewater facilities.

Clean Water Fund investment — Clean Water Fund dollars resulting from passage of the Clean Water, Land and Legacy Amendment will continue to accelerate the implementation of practices to improve and protect Minnesota’s water resources. However, Clean Water Funds available for implementation are not keeping pace with the demand from local governments and landowners.

https://www.pca.state.mn.us/water/nutrient-reduction-strategy


https://www.pca.state.mn.us/featured/report-nitrogen-surface-water


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Air pollutant emissions overview Thousands of chemicals are emitted into the air. Many of these are air pollutants that can directly or

indirectly affect human health, reduce visibility, cause property damage and harm the environment. For

these reasons, the MPCA attempts to reduce the amount of pollutants released into the air. In order to

understand the sources of air pollution and to track the success of reduction strategies, the MPCA

estimates the emissions of certain air pollutants released in Minnesota.

The Minnesota Emission Inventory estimates emissions from permitted facilities every year in order to

fulfill Minnesota rules. In addition, federal rules require the MPCA to estimate emissions every three

years from three other principal source categories: non-permitted sources, mobile sources, and fire

sources. Biogenic sources include emissions from natural sources such as soils and vegetation. This

report only includes manmade sources. Overall, the Minnesota Emission Inventory includes emissions

from four principal source categories.

1. Permitted sources: Typically large, stationary sources with relatively high emissions, such as electric

power plants and refineries. A "major" source emits a threshold amount (or more) of at least one

criteria pollutant, and must be inventoried and reported.

2. Non-permitted sources: Typically stationary sources, but generally smaller sources of emissions than

point sources. Examples include dry cleaners, gasoline service stations and residential wood

combustion. These sources do not individually produce sufficient emissions to qualify as point

sources. For example, a single gas station typically will not qualify as a point source, but collectively

the emissions from many gas stations may be significant.

3. Mobile sources: Mobile sources are broken up into two categories: on-road vehicles and off-road

sources. On-road vehicles include vehicles operated on highways, streets and roads. Off-road

sources include off-road vehicles and portable equipment powered by internal combustion engines.

Lawn and garden equipment, construction equipment, aircraft and locomotives are examples of off-

road sources.

4. Fires: Fire emissions are produced by inadvertent or intentional agricultural burning, prescribed

burning or forest wild fires.

Criteria pollutants—The 1970 Clean Air Act identified six major air pollutants that were present in high

concentrations throughout the United States known as “criteria pollutants.” These air pollutants are

particulate matter (PM2.5 and PM10), sulfur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), carbon

monoxide (CO) and lead (Pb). The Minnesota Criteria Pollutant Emission Inventory estimates emissions

of five criteria pollutants (PM10, SO2, NOx, CO and Pb) as well as a group of ozone precursors called

volatile organic compounds (VOCs). Emissions estimates for large facilities are available for 2016. Draft

2014 emissions are available for non-permitted, mobile and fire sources.

PM2.5 and ammonia (which is tracked because it contributes to PM2.5 formation) yearly emission

calculations for permitted facilities started in 2012, while non-permitted, mobile, and fire are still

calculated on a three-year cycle, with latest draft estimates available for 2014. Fire emissions depend on

many factors including type of fire, ecosystem conditions, and weather. As a result, fire emissions vary

greatly from year to year. Similarly, biogenic emissions are widespread and contribute to background air

pollution concentrations. They are impacted by vegetation, temperature and solar radiation. Biogenic

emission estimates are not included in this report.

Greenhouse gases—Increases in ambient levels of greenhouse gases can lead to global climate change.

The MPCA tracks and reports emissions for six greenhouse gases (carbon dioxide (CO2), nitrous oxide,

methane, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride) in terms of CO2 equivalents


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(CO2e). CO2e compares the warming potential of different gases to the impact of CO2. Emission

estimates for 2014 are included in this report. Federal and state rules require MPCA to estimate GHG

emissions from permitted sources each year. Starting in 2011, small permitted sources started reporting

GHG emissions. In 2012, all permitted point sources began submitting GHG emissions to the MPCA.

—Many other air pollutants are released in smaller amounts than most of the criteria

pollutants, but may still be toxic. The EPA refers to chemicals that can cause serious health and

environmental hazards as hazardous air pollutants or air toxics. Air toxics include chemicals such as

benzene, formaldehyde, acrolein, mercury and polycyclic aromatic hydrocarbons (PAHs). Air toxic

emissions from all sources are estimated every three years. Minnesota data comes from the draft 2014

Minnesota Air Toxics Emission Inventory.

With each new inventory, improvements are made in terms of pollutants covered, source categories

included, and the accuracy of emission estimates. Therefore, changes in the way emissions are

calculated may affect trends, even if there was no real increase or decrease in emissions.

The reader may note differences in the total emission figures for a given year discussed in this report,

versus previous emission reports the MPCA has published, because data may be updated in past

emission inventories due to corrections or changes in methodology.

This report shares summarized statewide emissions of air pollutants. A detailed breakdown of finalized

2014 air emissions will be available online on the MPCA website in the spring of 2018. MPCA has

developed multiple workbooks containing permitted source, statewide and county-level emissions. The

applications contain permitted source data going back to 2006 and statewide data starting in 2008. The

workbooks are a way for MPCA to share data in an automated, interactive and user-friendly format.

For more information, see the following websites:

https://www.pca.state.mn.us/air/air-emissions

https://www.pca.state.mn.us/air/statewide-and-county-air-emissions

https://www.pca.state.mn.us/air/point-source-air-emissions-data

Criteria air pollutant emissions

Minnesota’s Emission Inventory Rule requires all facilities in Minnesota that have an air emissions

permit to submit an annual emission inventory report to the MPCA. The report quantifies emissions of

the following regulated pollutants:

Particulate matter less than 10 microns in diameter (PM10) is a broad class of chemically and physically diverse substances that exist as discrete particles (liquid droplets or solids) over a wide range of sizes. EPA currently has National Ambient Air Quality Standards for particulate matter in two size classes, PM2.5 and PM10. PM2.5 and PM10 are associated with numerous adverse health effects. Fine particles are the major cause of reduced visibility in parts of the United States. In addition, when particles containing nitrogen and sulfur deposit onto land or waters, they may affect nutrient balances and acidity. Finally, different types of particulate matter, for example black carbon (soot) and sulfate particles, play a role in climate change.

Sulfur dioxide (SO2) belongs to the family of sulfur oxide gases and forms when fuel-containing sulfur (mainly coal and oil) is burned and during gasoline production and metal smelting. Short-term exposures to SO2 is linked with adverse respiratory effects. SO2 also reacts with other chemicals in the air to form tiny sulfate particles and acids that fall to earth as rain, fog, snow, or

https://www.pca.state.mn.us/air/air-emissions

https://www.pca.state.mn.us/air/statewide-and-county-air-emissions

https://www.pca.state.mn.us/air/point-source-air-emissions-data


9

dry particles. Acid rain damages the environment, accelerates the decay of buildings and monuments and is a major component of haze.

Nitrogen oxides (NOx) are made up of two primary constituents: nitric oxide (NO) and nitrogen dioxide (NO2). NO is a colorless, odorless gas that is readily oxidized in the atmosphere to NO2. NO2 exists as a brown gas that gives photochemical smog its reddish-brown color. NOx forms when fuel is burned at high temperatures. NO2 exposure is linked with adverse respiratory effects. It is also a major precursor both to ozone and to fine particulate matter (PM2.5). Deposition of nitrogen can lead to many environmental problems including fertilization, acidification of terrestrial, wetland and aquatic systems, increased visibility impairments and others. Nitrous oxide (N2O), another component of NOx, is a greenhouse gas.

Volatile organic compounds (VOCs) are compounds containing the elements carbon and hydrogen that exist in the atmosphere primarily as gases because of their low vapor pressure. VOCs are defined in federal rules as chemicals that participate in forming ozone. Many VOCs are also air toxics and can have harmful effects on human health and the environment.

Carbon monoxide (CO) is a colorless and odorless toxic gas formed when carbon in fuels is not burned completely. A major source of CO is motor vehicle exhaust. Exposure to elevated CO levels is associated with impaired visual perception and work capacity among others, and can lead to death. At concentrations commonly found in the ambient air, CO does not appear to have adverse effects on plants, wildlife or materials. However, CO is oxidized to form carbon dioxide (CO2), a major greenhouse gas and it contributes to the formation of ground-level ozone.

Lead (Pb) is a naturally occurring element. Major sources of lead emissions were motor vehicles and industrial sources. Since lead in gasoline was phased out, air emissions and ambient air concentrations have decreased dramatically. Currently, metals processing (lead and other metals smelters) and aircraft using leaded fuel are the primary sources of lead emissions. There are no known safe levels of lead in the body. Chronic exposure or exposure to higher levels can result in multiple effects, including damage of the kidneys and nervous system in both children and adults. Elevated lead levels are also detrimental to animals and to the environment.

The Minnesota Criteria Pollutant Emission Inventory is complete for permitted sources through 2016.

The figure below shows emission trends for permitted sources since 2005. These emissions have

decreased significantly over the past decade largely due to governmental regulations and industry

efforts to reduce emissions. As mentioned elsewhere in this report, emissions of nitrogen oxides and

sulfur dioxide have decreased significantly in the past decade due to facilities switching from coal to

natural gas and installing new pollution controls on their units. Mining production has also decreased

over the last few years, further reducing emissions.

Figure 4. Minnesota permitted source emissions 2005-2016

There has been a reduction in all criteria pollutant emissions from 2008 to 2014 (the most recent years

we have emission estimates from all sources). Figure 5 shows the statewide total in emissions from

nitrogen oxide, sulfur dioxide, volatile organic compounds and particulate matter. Emissions from all

source types (mobile, non-permitted and permitted sources) have decreased by about a third since

2008.


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Table 1 shows statewide emissions for major criteria air pollutants and percent changes from 2014 to 2016. Despite the importance of secondary formation in creating particulate matter and some other pollutants, it is important to note that estimated air emissions data in this report are only based on direct releases from sources into the atmosphere. Emissions decreased for all pollutants from 2014 to 2016.

Table 1. Minnesota Air Pollution Emission Estimates 2014 to 2016 (tons)

Pollutant 2014 2015 2016 2014-2016 %

change*

Particulate matter (PM10)**

1,092,636 1,088,264 1,087,039 -0.5

Sulfur dioxide (SO2)

46,374 34,351 30,652 -34

Nitrogen oxides (NOx)

256,815 241,113 237,792 -7

Volatile organic compounds (VOCs)

224,296 224,175 223,755 -0.2

Particulate matter (PM2.5)**

125,440 121,316 120,963 - 4

Lead (Pb)

17 17 15 -7

Total Criteria Pollutants

3,060,840 3,023,578 3,014,359 -1.5

* Draft 2014 mobile and nonpoint emissions estimated were used in the 2014 to 2016 emissions estimates. The only changes are from point sources.

** PM10 and PM2.5 emissions represent only direct emissions; secondary formation is not included.

0

200,000

400,000

600,000

800,000

1,000,000

2008 2011 2014 (draft)

Emis

sio

ns

(To

ns)

Year

Non-permitted sources Off-road vehicles and equipment

On-road vehicles Permitted sources

Figure 5. Criteria air pollutant statewide emission trends


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Air toxics

The EPA defines air toxics as pollutants that cause or may cause cancer or other serious health effects,

such as reproductive effects or birth defects, or adverse environmental and ecological effects.

The Minnesota Air Toxics Emission Inventory estimates emissions of air toxics from all sources every

three years. The majority of pollutants with MPCA emission estimates are part of EPA’s hazardous air

pollutant group. The most recent completed inventory for Minnesota is 2011; however, 2014 draft data

are available and will be the focus of this report. The inventory includes four principal source categories:

permitted, non-permitted, mobile and fire sources.

MPCA staff compiled the emissions estimates for permitted and the majority of non-permitted sources

in the 2014 inventory. Emissions for wildfires and prescribed burning were obtained from EPA. The

results for aircraft (including ground support equipment), locomotives and commercial marine vessels

were also estimated by EPA. For all off-road equipment and on-road vehicles, MPCA used estimates

from EPA’s national inventory.

The following chart summarizes 2014 draft statewide emissions from directly emitted air toxics

pollutants. It does not include secondarily formed pollutants. Once finalized 2014 data is available, the

breakdown of air toxics categories may change. Non-permitted sources include very small stationary

sources such as auto body shops and dry cleaners. These account for 19% of emissions. Mobile sources,

including both on-road vehicles such as cars and trucks and off-road equipment such as recreational

vehicles and agriculture equipment, account for over 60% of total emissions. Large permitted facilities

contributed 5% and fires accounted for 13% of the total. Biogenic emissions are not included in the

breakdown because they depend on many environmental factors such as weather, background and

ecosystem conditions that are largely uncontrolled by human activity.

For more details about 2014 air toxics emissions, please visit the online application. This application will be updated with 2014 data once finalized emissions become available. MPCA developed multiple workbooks containing permitted sources, statewide and county level emissions. End users have hands-on access to emissions data, which they can view and use in an interactive format. Web applications contain statewide data going back to 2008.

Figure 6. Sources of air toxics emissions in Minnesota, 2014


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Greenhouse gases

Greenhouse gases (GHGs) warm the atmosphere and surface of the planet, leading to alterations in the

earth’s climate. Many greenhouse gases occur naturally, but burning fossil fuels and other human

activities are adding these gases to the natural mix at an accelerated rate. In 2014, Minnesota’s GHG

emissions were estimated to be 158.3 million CO2e tons. CO2e compares the global warming potential of

emissions of different gases to the impact of the emission of one ton of CO2. Most of Minnesota’s GHG

emissions are the result of using fossil fuel energy for electricity generation, transportation, heating, and

other uses. Figure 7 shows GHG emissions by economic sector. The largest source of emissions is from

the generation of electricity. GHG emissions from electricity generation include emissions from

electricity generated in other states to meet Minnesota’s net electricity demand. Over half of the GHG

emissions from the transportation sector are from passenger and light-duty vehicles. Other significant

sources include heavy-duty trucks, aviation, and natural gas transmission in pipelines.

Figure 7. 2014 sector GHG emissions, storage sources, and sector percent of total

Trends in Minnesota’s greenhouse gas emissions

Trends in emissions over time let us see the effects of policies and other factors that might change

emissions. Since 2005, Minnesota’s total greenhouse gas emissions have declined by about 4%. Each

economic sector shows a unique trend in emissions.

The Next Generation Energy Act of 2007 (Minn. Stat. § 216H.02) established a 2015 GHG emission

reduction goal 15% below 2005 emissions, and longer-term goals for 2025 (30% below 2005 emissions),

and 2050 (80% below 2005 emissions).


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Figure 8. Minnesota’s GHG emissions 1990-2014 and goals

References/web links

For more information on climate change in Minnesota, greenhouse gas emissions, and initiatives to

reduce emissions and adapt to a changing climate, see the following website: https://www.pca.state.mn.us/air/climate-change-minnesota

Mercury

Exposure to mercury can harm the nervous system, posing the greatest risk to a developing fetus and

fish-eating wildlife. For most Minnesotans, eating fish contaminated with unhealthy levels of mercury

poses the greatest risk of exposure. While fish are a desired source of protein and other nutrients,

citizens are advised to limit their consumption of larger predatory fish. Consult the Minnesota

Department of Health (MDH) Fish Consumption Advisory for guidelines to specific lakes and rivers at

http://www.health.state.mn.us/divs/eh/fish/eating/sitespecific.html.

Mercury emissions are transported through the atmosphere and deposited by rain into Minnesota’s

lakes and rivers. Of the waters tested in the state, roughly two-thirds are impaired for mercury. To

achieve necessary reductions of mercury in fish, the MPCA developed a statewide mercury Total

Maximum Daily Load (TMDL) study. The TMDL establishes a goal of 93% reduction in mercury from all

human sources including emissions originating from outside of Minnesota. The MPCA is working to meet

the 93% reduction in the state by following the mercury TMDL implementation plan, developed by

stakeholders in 2009. In order to evaluate the progress of reducing mercury in our waters, mercury

emissions inventories are developed and tracked, and the subsequent response in fish tissue is

documented.

All lakes and rivers within Minnesota will benefit from the reduced mercury emissions from

accomplishing the goals of the statewide TMDL implementation plan. The TMDL demonstrated that

mercury deposition was essentially uniform throughout the state and that deposition represented 99%

of the mercury source to lakes and rivers in the state. Despite the uniform deposition of mercury, about

https://www.pca.state.mn.us/air/climate-change-minnesota

http://www.health.state.mn.us/divs/eh/fish/eating/sitespecific.html


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10% of Minnesota surface waters may not meet the water quality standard after the mercury emissions

goal is achieved, because these waters are more efficient at concentrating mercury into fish. Scientists

understand some of the factors that cause this enhanced mercury accumulation, but not well enough to

know the relative importance of each factor and what actions could reduce the enhanced mercury

accumulation. MPCA’s scientific research into the unusually high mercury concentrations in fish in some

Minnesota rivers was funded by the Legislative-Citizen Commission on Minnesota Resources (LCCMR) in

2014 and continued through June 2017 (https://www.lccmr.leg.mn/projects/2014-index.html#201403j)

MPCA staff and collaborating academic scientists are continuing to analyze the large acquired dataset.

MPCA will pursue additional funding from other sources for the remainder of the research.

Sector activities and reductions

A number of efforts are in place to reduce mercury emissions. The state’s power utilities achieved

reductions ahead of schedule achieving the goals of the Minnesota Mercury Emissions Reduction Act of

2006 and the mercury TMDL. The 2016 emissions are draft and currently being analyzed, and therefore

not included in this report. It is estimated that electric utilities emitted an approximate 173 pounds of

mercury in 2016 and are estimated to represent the smallest of the three source categories. This is a

remarkable decrease from 1,867pounds emitted in 2005.

The taconite mining sector continues its research to test possible mercury-reduction technologies and is

required to submit reduction plans to the MPCA in December 2018. The plans will describe how the

goals of the TMDL will be met by year 2025.

The MPCA continues to work to improve the confidence interval of the mercury emissions inventory

through partnerships and research. Research to improve emissions estimates with crematories is

complete and a new emission factor developed. Additional work has been identified with industries such

as waste haulers, appliance recyclers and other metal smelters.

https://www.lccmr.leg.mn/projects/2014-index.html#201403j


15

Figure 9. Mercury emission from Minnesota sources: 2005 through 2014

Mercury concentration in Minnesota fish

The trend in fish-mercury concentrations reported in previous versions of this report focused on 1982 to

the present. However, a re-examination of the data showed fish collection prior to 1990 was focused on

lakes in northern Minnesota, a region where mercury concentrations are generally higher than the state

average and that a long-term trend analysis could be biased if the pre-1990 samples were included. As a

result, MPCA scientists are now using walleye and northern pike collected since 1990 to examine the

change in mercury concentrations in lakes over time.

What progress has been made? The 27-year fish-mercury trend from 1990 to 2016 shown in Figure 10

indicates a different pattern than has been reported in previous years. Data from lakes sampled starting

with 1990 as the baseline year show an upward trend in average mercury concentration. The increase,

0.37% per year on average, is significant. Minnesota’s water standard for mercury in edible fish tissue –

200 parts per billion (ppb) – is shown for reference on the figure, because it is the threshold above

which lakes and streams are impaired. The standard protects humans for consumption of one meal per

week of fish caught in Minnesota. MPCA scientists plan to update the fish mercury trend analysis after

an additional five years of data are available. More explanation of the mercury trends in fish is available

in the 2018 Clean Water Fund Performance Report http://www.legacy.leg.mn.

3,312

2,8432,705

1,274

1,564

2,279

http://www.legacy.leg.mn/


16

Figure 10. Trend of mercury in northern pike and walleye from Minnesota lakes: 1990-2016

References/web links

For more information on mercury, see the following websites:

MPCA’s mercury emission inventory: https://www.pca.state.mn.us/sites/default/files/wq-iw4-02g5.pdf

MPCA’s mercury webpages: https://www.pca.state.mn.us/quick-links/mercury

UN Environment, Global Mercury Partnership: http://web.unep.org/chemicalsandwaste/global-

mercury-partnership

https://www.pca.state.mn.us/sites/default/files/wq-iw4-02g5.pdf

https://www.pca.state.mn.us/quick-links/mercury

http://web.unep.org/chemicalsandwaste/global-mercury-partnership

http://web.unep.org/chemicalsandwaste/global-mercury-partnership


17

Water pollutant discharges overview Minnesota’s rivers, streams and lakes provide great natural beauty, and supply the water necessary for

recreation, industry, households, agriculture and aquatic life. The major goal of the MPCA’s water

quality program is to enable Minnesotans to protect and improve the state’s rivers, lakes, wetlands and

groundwater so that they support healthy aquatic communities and designated public uses such as

fishing, swimming and drinking water. The key strategies for accomplishing this goal include regulating

point source discharges, controlling nonpoint sources of pollution, and assessing water quality to

provide data and information to make sound environmental management decisions.

Point sources consist mainly of municipal and industrial wastewater discharges. Point sources have the

greatest potential to impact the environment during periods of low precipitation and low stream flow.

Nonpoint sources include runoff from agricultural fields, feedlots, urban areas, and on-site sewage

treatment (septic) systems. Nonpoint sources are most significant during periods of high precipitation

and medium to high stream flow.

Minnesota has been largely successful in controlling end-of-pipe discharges to our state’s waters from

wastewater treatment plants and industries. However, at the same time, the challenges posed by

nonpoint sources of pollution are increasing as land use changes and population expands. The federal

Clean Water Act requires states to adopt water quality standards to protect the nation’s waters. These

standards define how much of a pollutant can be in a surface or groundwater supply while still allowing

it to meet its designated uses, such as for drinking water, fishing, swimming, irrigation, aquatic life or

industrial purposes.

For each pollutant that causes a water to fail to meet state water quality standards, the federal Clean

Water Act requires the MPCA to conduct a TMDL study. A TMDL study identifies both point and

nonpoint sources of each pollutant that fails to meet water quality standards. While lakes, rivers and

streams may have several TMDLs, each determining the limit for a different pollutant, the state has

moved to a watershed approach that addresses multiple pollutants and sites within a watershed to

efficiently complete TMDLs. Many of Minnesota’s water resources cannot currently meet their

designated uses because of pollution from a combination of point and nonpoint sources.

Wastewater discharges

Owners or operators of any disposal system or point source are required by Minnesota law to obtain

permits, maintain records and make reports of any discharges to waters of the state. These self-

monitoring reports submitted to MPCA are commonly referred to as Discharge Monitoring Reports

(DMRs). DMR data are compiled using compliance tracking data systems maintained by MPCA data

specialists.

The MPCA’s water quality program continues to evolve from a predominantly concentration-based,

facility-by-facility regulatory approach to one that emphasizes managing total pollution discharges to

Minnesota’s watersheds. The current report represents a continuing effort to improve the MPCA’s

capacity to accurately perform loading analyses. Due to the five-year permit cycle, however, some

permits have yet to be modified for select pollutants to incorporate the monitoring and reporting

requirements necessary to enable efficient, computerized calculations of total annual pollutant loadings.

As the MPCA reissues permits and conducts ongoing review of data, it will continue to build capability in

this area and the assessment of pollutant trends over multiple years will become more reliable.


18

Overall pollutant loads to receiving waters are based on a combination of effluent flow and pollutant

concentrations in the effluent. Loads are calculated by combining facility-reported flow and

concentration data. If facility-specific data are not available, loads are estimated with information based

on facilities with similar waste streams or other best professional judgment. Effluent flow and pollutant

loading estimates for National Pollution Discharge Elimination System (NPDES) permitted facilities

exclude once-through non-contact cooling water data from power generation facilities—large volumes

of (primarily) river water used for cooling purposes. These once-through non-contact cooling waters are

discharged with the addition of heat, and with minor additions of other pollutants. Pollutant loads

associated with these discharges were largely present in the waterbodies before the waters were

withdrawn for cooling purposes so reporting them as wastewater pollutants would be misleading.

Pollutant loads calculated from measured wastewater flows and observed pollutant concentrations are

considered to be highly reliable while less confidence is warranted for pollutant loads derived from

estimated concentrations. The degree of confidence in each loading estimate can be expressed as the

proportion of the load derived from observed values compared to the proportion derived from

estimated values. The loading graphs in this report are color coded by ‘Observed’ and ‘Estimated’ to

serve as a confidence measure for each pollutant load measure.

Prior to 2014, the wastewater sections of the MPCA’s Pollution Reports to the Legislature were based on

data reported by approximately 99 major wastewater dischargers. These are facilities permitted to

discharge at least 1 million gallons of treated wastewater per day and account for approximately 85% of

the volume of treated wastewater discharged to waters of the state. Reports now include data from all

surface water dischargers, regardless of size. The inclusion of non-major facilities provides a more

complete measure of pollutant loads since non-major facilities can collectively impact water quality.

Figure 11 shows the distribution of municipal wastewater facilities by size.


19

Figure 11. Distribution of municipal wastewater facilities by size


20

The map below shows the distribution of industrial discharges by type. Facilities are grouped in the

following broad categories: agricultural industry, food processing, mining (including non-metallic mining

operations), power plants and other.

Figure 12. Distribution of industrial wastewater dischargers by type

Five common chemical parameters found in wastewater treatment plant effluent are highlighted in this

report: total suspended solids (TSS), carbonaceous biochemical oxygen demand (CBOD5), total

phosphorus, total nitrogen and mercury.

Effluent flow volumes are also included this report. Although flow is not a regulated pollutant, it is a

useful gauge of overall facility performance because of the direct relationship between pollutant loading

and effluent flow volume. For example, if effluent flow and pollutant loading show proportional annual

increases, it is an indication that overall effluent concentrations have remained stable and the loading

increase is attributable to the increase in flow. Conversely, if the pollutant load showed consistent

annual decreases despite an increase in effluent flow volume, the concentration has likely decreased

and the effluent quality has improved.

Table 2 summarizes effluent pollutant loading and flow volume estimates for municipal and industrial

wastewater treatment facilities in Minnesota from 2000 to 2017.


21

Flow

Overall, wastewater flow volumes have fluctuated from a baseline of 270 billion gallons per year in

2000/2001 to a peak of 304 billion gallons per year in 2011. Average effluent flow from 2013 through

2017 was 283 billion gallons/year. Since the year 2000, major facilities have discharged approximately

78% of the total treated wastewater. Municipal wastewater treatment facilities discharged 64% of the

total treated wastewater from 2000 through 2004. Since 2005, the proportion of municipal wastewater

flow has declined to 59% of the total. Wastewater flow reductions have occurred since 2011. 2012 was a

particularly dry year, which affected the volume of water being processed by municipal wastewater

treatment facilities. However, despite increasing precipitation and higher stream flows in subsequent

years, changes in wastewater flows remained relatively modest. From 2014 to 2017, surface water

discharges reported by the wastewater sector have averaged 286 billion gallons per year, a slight

increase from the long-term average.

Figure 13. Minnesota wastewater effluent flow for 2017


22

Point source pollutant loading trends

Figure 14 shows pollutant effluent flows and loading trends for TSS, CBOD5, total phosphorus and total

nitrogen from 2000 – 2017. Mercury trends from wastewater treatment facilities are shown in Figure 22

on page 35. Overall, effluent flows tend to fluctuate based on the amount of rainfall and snow melt. The

overall health of the economy also affects the amount of industrial production, which in turn affects

industrial effluent flows and the amount of industrial effluent treated at municipal wastewater

treatment facilities. Overall trends include:

TSS loads: Stable –TSS loads increased in 2001 and 2002 but have otherwise remained fairly stable at

approximately 5,000 metric tons per year.

CBOD5 loads: Declined—Loads have declined from loads ranging from 3,000 to 4,000 metric tons per

year during the 2000 to 2004 period to an average load of 2,400 tons per year since 2005.

Total phosphorus loads: Declined--Significant total phosphorus reductions have been achieved since

2000.

Total nitrogen loads: Increased—Total nitrogen loads have increased from 13,000 metric tons per year

in 2000/2001 to 15,000 metric tons per year in 2016/2017. The long-term 2000 -2017 average

phosphorus effluent load is 13,700 metric tons per year.

Mercury loads: Decreased—Significant mercury load reductions have been achieved. Mercury loads

prior to 2005 are excluded because of changes in the ability to detect mercury in effluent.

Figure 14. Pollutant loading trends from Minnesota wastewater facilities, 2000-2017


23

Table 2 shows pollutant effluent flow and loading trends from 2000 through 2017. Effluent flow is

reported in billion gallons per year. Pollutant loads for TSS, CBOD5, total phosphorus and total nitrogen

are reported in metric tons per year. Pollutant loads for mercury are reported in kilograms per year.

Table 2. Annual total flow and pollutant load

Flow (MG/year)

TSS (MT/year)

Total phosphorus

(MT/year) CBOD5

(MT/year)¹

Total nitrogen

(MT/year)

Mercury

(Kg/year)²

2000 258,476 5,429 1,841 3,350 12,457 -

2001 280,737 8,836 1,860 4,893 13,673 -

2002 281,585 7,881 1,733 4,355 13,582 -

2003 260,201 6,430 1,405 3,664 12,572 -

2004 271,917 5,708 1,224 3,087 12,948 -

2005 289,444 5,916 1,080 2,605 13,606 4.2

2006 293,900 5,757 1,089 2,402 13,348 3.9

2007 294,131 6,045 1,027 2,419 13,367 3.2

2008 295,388 5,368 971 2,577 13,132 2.8

2009 283,705 5,136 823 2,259 12,684 2.6

2010 292,249 5,473 794 2,428 14,069 3.0

2011 303,759 5,967 776 2,851 15,067 3.2

2012 269,183 4,673 640 2,232 13,747 2.0

2013 273,402 4,687 619 2,205 14,123 2.3

2014 285,805 5,046 599 2,473 14,541 2.8

2015 267,352 4,195 548 2,031 13,951 2.3

2016 294,670 5,310 584 2,557 14,587 2.2

2017 294,588 4,855 592 2,437 15,279 2.2

¹Industrial facilities are excluded from CBOD5 load calculations due to lack of data. ²Peat mining facilities are excluded from mercury calculations due to unreliability of flow and mercury data.


24

Table 3 shows flow-weighted mean concentration (FWMC) trends from 2000 through 2017. FWMC is

calculated by dividing the annual load by the annual flow and is a measure of the overall performance of

wastewater dischargers. All FWMCs are reported in milligrams per liter (mg/L) except for mercury, which

is reported in nanograms per liter (ng/L). TSS FWMCs have remained fairly stable at approximately

5 mg/L. CBOD5 FWMCs have declined from approximately 3 mg/L in the 2000 to 2004 period to

approximately 2 mg/L since 2005. Total phosphorus FWMCs have declined from approximately 1.5 mg/L

in the 2000 to 2003 time period to approximately 0.5 mg/L in from 2014 to 2017. Total nitrogen FWMCs

have increased approximately 1 mg/L. Mercury concentrations declined from approximately 4 ng/L in

2005 to approximately 2 ng/L since 2015.

Table 3. Annual flow-weighted mean concentration

TSS (mg/L)

CBOD5 (mg/L)

Total phosphorus

(mg/L)

Total nitrogen (mg/L)

Mercury (ng/L)

2000 5.55 3.42 1.88 12.73 -

2001 8.32 4.60 1.75 12.87 -

2002 7.39 4.09 1.63 12.74 -

2003 6.53 3.72 1.43 12.77 -

2004 5.55 3.00 1.19 12.58 -

2005 5.40 2.38 0.99 12.42 3.79

2006 5.18 2.16 0.98 12.00 3.53

2007 5.43 2.17 0.92 12.01 2.91

2008 4.80 2.30 0.87 11.75 2.54

2009 4.78 2.10 0.77 11.81 2.43

2010 4.95 2.19 0.72 12.72 2.69

2011 5.19 2.48 0.68 13.10 2.76

2012 4.59 2.19 0.63 13.49 1.94

2013 4.53 2.13 0.60 13.65 2.23

2014 4.66 2.29 0.55 13.44 2.63

2015 4.15 2.01 0.54 13.79 2.31

2016 4.76 2.29 0.52 13.08 1.94

2017 4.35 2.19 0.53 13.70 1.98


25

Table 4 shows the percent change in annual flow and pollutant loads. 2001 stands out as a year that saw

significant increases in the loading of all pollutants, probably as a result of the significant flooding that

occurred that year. Excluding 2001, the year-to-year percent change data show the following:

An average 3% per year decline in annual TSS loads

An average 3% per year decline in annual CBOD5 loads

An average 7% per year decline in annual total phosphorus loads

An average 1% per year increase in annual total nitrogen loads

An average 4% per year decline in annual mercury

Table 4. Percent change in annual flow and pollutant loads

Flow (%) TSS (%) CBOD5 (%)

Total

phosphorus (%)

Total nitrogen

(%) Mercury

(%)

2000

2001 9% 63% 46% 1% 10% -

2002 0% -11% -11% -7% -1% -

2003 -8% -18% -16% -19% -7% -

2004 5% -11% -16% -13% 3% -

2005 6% 4% -16% -12% 5% -

2006 2% -3% -8% 1% -2% -5%

2007 0% 5% 1% -6% 0% -18%

2008 0% -11% 7% -5% -2% -12%

2009 -4% -4% -12% -15% -3% -8%

2010 3% 7% 7% -4% 11% 14%

2011 4% 9% 17% -2% 7% 6%

2012 -11% -22% -22% -18% -9% -38%

2013 2% 0% -1% -3% 3% 17%

2014 5% 8% 12% -3% 3% 23%

2015 -6% -17% -18% -9% -4% -18%

2016 10% 27% 26% 7% 5% -8%

2017 0% -9% -5% 1% 5% 2%

Table 5 on the next page shows the percent change in annual flow and pollutant load values from a

baseline defined as the average of the years 2000 and 2001. Percent change since 2002 from baseline

data show:

An average 5% increase in effluent flows

An average 22% decrease in TSS loads

An average 35% decrease in CBOD5 loads

An average 51% decrease in total phosphorus loads

An average 6% increase in total nitrogen loads

An average 35% reduction in mercury loads (baseline 2005-06 due to change in detection level)


26

Table 5. Percent change in annual (values) from baseline

Flow (%) TSS (%)

Total phosphorus

(%)

CBOD5 (%)

Total nitrogen (%)

Mercury* (%)

2000-01 Baseline

269,607 (MG/year)

7,133 (MT/year)

1,851 (Mt/year)

4,122 (MT/year)

13,065 (MT/year)

4.05 (Kg/year)

2002 4% 10% -6% 6% 4% -

2003 -3% -10% -24% -11% -4% -

2004 1% -20% -34% -25% -1% -

2005 7% 17% -42% -37% -4% -

2006 9% -19% -41% -42% 2% -

2007 9% -15% -45% -41% 2% -21%

2008 10% -25% -48% -37% 1% -31%

2009 5% -28% -56% -45% -3% -36%

2010 8% -23% -57% -41% 8% -26%

2011 13% -16% -58% -31% 15% -21%

2012 0% -34% -65% -46% 5% -51%

2013 1% -34% -67% -47% 8% -43%

2014 6% -29% -68% -40% 11% -31%

2015 -1% -41% -70% -51% 7% -43%

2016 9% -26% -68% -38% 12% -46%

2017 9% -32% -68% -41% 17% -46%

* Mercury baseline is 2005-2006 due to change in detection level.

A number of additional sources of variation, both up and down, can potentially impact year-to-year

comparisons.

The loading calculations incorporate data interpretation decisions that can legitimately be made in a variety of ways. This typically applies to the classification of waste-stream and facility types for the assignment of categorical concentrations. There are also select facilities that report highly inconsistent values for some parameters and are excluded until the questionable values can be verified.

Reporting requirements can vary with each permit issuance, resulting in variation in parameters, limit types, and reporting periods, and making year-by-year comparisons difficult. Additionally, when a facility does not monitor a pollutant in a month that it discharges, the concentration for that month is presumed to be the average annual concentration.

Wastewater treatment facilities regularly experience variations in influent strength, influent flow and facility performance that may not be fully reflected in the data used to generate this report.


27

Total suspended solids (TSS)

Total suspended solids (TSS) is a measure of the material suspended in water or wastewater. TSS causes

interference with light penetration, buildup of sediment, potential degradation of aquatic habitat and

harm to aquatic life. Suspended solids also carry nutrients that cause algal blooms that are harmful to

fish and other aquatic organisms.

The TSS load for 2017 was 4,855 metric tons, a 2% increase from the 2015-16 average. Long-term

average TSS wastewater loading has remained relatively stable over the past decade. On average, the

data show an overall 32% reduction in annual TSS loads from a 7,133 metric ton per year baseline in

2000/2001 (Figure 15).

Wastewater TSS data are considered reliable, with 95% of loads resulting from observed data points. On

average, 72% of wastewater TSS loads are discharged by major facilities although this proportion has

declined from an average of 78% from 2000 through 2003 to an average of 70% from 2004 through

2017. On average, municipal wastewater dischargers accounted for 84% of wastewater TSS loads from

2000 through 2003 while their proportion of wastewater TSS loading declined to an average of 68%

from 2004 through 2017. Overall, wastewater TSS loads have declined from an average of 7,144 metric

tons per year in the 2000 through 2003 period to an average of 5,160 metric tons per year from 2007

through 2017.

TSS is one of the most frequently monitored pollutants in wastewater. Most facilities have technology-

based effluent limits, which, in most cases, are more restrictive than limits needed to meet TSS water

quality standards. As a result, most facilities are discharging below a concentration level of concern and

future wastewater TSS reductions are not generally necessary. Nonetheless, advanced treatment

required to meet other effluent limits for pollutants such as phosphorus and mercury may result in

further TSS reductions since those pollutants tend to be components of or attached to suspended solids.

Figure 15. Annual wastewater loading values for total suspended solids (TSS)


28

Carbonaceous biochemical oxygen demand (CBOD5)

When organic wastes are introduced into water, they require oxygen to break down. The amount of

oxygen required for decomposition of organic wastes by microorganisms is known as the biochemical

oxygen demand (BOD), while carbonaceous biochemical oxygen demand (CBOD5) is the amount of

oxygen required for microorganisms to decompose carbonaceous waste materials. High concentrations

of organic materials characterize untreated domestic wastes and many industrial wastes. Both BOD and

CBOD5 are indicators of the strength of wastewater effluent and the effectiveness of treatment. A high

demand for oxygen causes reduction in the concentration of oxygen in the receiving waters. Depletion

of oxygen adversely impacts aquatic life.

Municipal wastewater treatment facility effluent limitations and reporting requirements are expressed

as CBOD5. Industrial dischargers most frequently report BOD, which reflects the industry-specific

requirements within Federal Regulations. For purposes of this report, CBOD5 was used for load

calculations because it provides a more complete data set for municipal loading calculations. Industrial

facilities are not included in this calculation because there are too few observations to confidently

estimate categorical concentrations. The complete BOD/CBOD5 load could be significantly higher than

the currently reported values because industrial flow accounts for nearly half of the flow within the

state.

The total municipal wastewater CBOD5 load for 2017 was 2,437 metric tons, a 6% increase from the

2015-2016 average. On average, the data show an overall 41% reduction in annual CBOD5 loads from a

4,122 metric ton per year baseline in 2000/2001 (Figure 16).

Municipal wastewater CBOD5 data are reliable, with 84% of values resulting from observed data points.

On average, 85% of wastewater CBOD5 loads are discharged by major facilities although the proportion

of CBOD5 loads discharged by major facilities has declined from an average of 89% from 2000-2003 to an

average of 83% from 2004-2017. Overall, wastewater CBOD5 loads have declined from an average of

4,066 metric tons per year in the 2000-2003 period to an average of 2,406 metric tons per year from

2007-2017.


29

Figure 16. Annual loading values for municipal wastewater carbonaceous biochemical oxygen demand (CBOD5)

Minnesota Nutrient Reduction Strategy (phosphorus and nitrogen)

Minnesota’s 2014 Nutrient Reduction Strategy identifies relative nutrient (phosphorus and nitrogen)

source contributions to surface waters. The strategy also establishes nutrient reduction goals for both

point and nonpoint sources (Table 6). In aggregate, wastewater sources have achieved the desired

phosphorus reductions and work to meet local water quality goals is in progress. Permit nitrogen

monitoring frequency requirements have increased as first step towards improving overall

understanding of the nitrogen concentrations and loads discharged by Minnesota wastewater facilities.

Wastewater nitrogen reductions specified for the Mississippi and Lake Winnipeg drainages have not yet

been achieved. The International Red River Board intends to adopt nutrient objectives for the Red River

in 2018.

Table 6. Timeline and reduction goals

a Timeline and reduction goals to be revised upon completion of the Red River/Lake Winnipeg strategy.

Major Basin Pollutant 2010 – 2025 2025 - 2040

Mississippi River (Includes the Cedar, Des Moines and Missouri Rivers)

Phosphorus Achieve 45% reduction goal

Work on remaining reduction needs to meet water quality standards

Nitrogen Achieve 20% reduction from baseline

Achieve 45% reduction from baseline

Lake Winnipeg a

(Red River only)

Phosphorus Achieve 10% reduction goal

Achieve any additional needed reductions identified through international joint efforts with Canada and in-state water quality standards

Nitrogen Achieve 13% reduction goal

Lake Superior Phosphorus Maintain goals, no net increase

Nitrogen Maintain protection



30

Total phosphorus

Total phosphorus is the primary pollutant associated with increased algae growth in Minnesota’s lakes

and streams. Excess phosphorus from human activities causes algae blooms and reduced water

transparency, making water unsuitable for swimming and other activities. Phosphorus is released from

both point and nonpoint sources of pollution.

Controlling phosphorus is an important part of protecting Minnesota’s water resources. Minnesota has

had point source effluent limitations for phosphorus since the early 1970s. Considerable reductions in

phosphorus from wastewater treatment facilities have been achieved since the MPCA Citizens Board

adopted a strategy for addressing phosphorus in NPDES permits in 2000. Phosphorus loads were

reduced by 56% from 2000-2009 and have decreased a further 28% since 2009. Overall, these efforts

have resulted in a steady decline of phosphorus pollution from point sources (Figure 17).

The 2017 total phosphorus load for the state was 592 metric tons, which increased 5% from the 2015-

2016 average of 569 metric tons. A 68% reduction in total phosphorus loads has been accomplished

from a 1,851 metric ton per year baseline in 2000/2001.

On average, 82% of wastewater total phosphorus loads are discharged by major facilities although the

proportion discharged by major facilities has declined from an average of 87% from 2000-2003 to an

average of 79% from 2004-2017. Municipal wastewater dischargers accounted for 91% of total

phosphorus loads from 2000 through 2003 with their proportion of the loading declining to an average

of 85% from 2004-2017. Overall, wastewater total phosphorus loads have declined from an average of

1,710 metric tons per year in the 2000-2003 period to an average of 1,078 metric tons per year from

2004-2008 and further to an average load of 644 metric tons per year from 2010-2017.

Figure 17. Annual total phosphorus loads from wastewater treatment facilities


31

Minnesota River Basin phosphorus reductions

Reductions in phosphorus loading to the Minnesota River have also occurred as a result of Minnesota

River Basin General Phosphorus Permit, which was issued on December 1, 2005. The permit was

developed as part of the Lower Minnesota River Dissolved Oxygen TMDL, which was completed to

address a dissolved oxygen impairment in the Lower Minnesota River. The permit required the 40

largest continuously discharging wastewater treatment facilities within the Minnesota River Basin to

apply for coverage and receive a five-month (May-September) mass phosphorus limit. The permit

required incremental reductions over time. The TMDL’s phosphorus reduction goal was met by 2012

(see graphic below).

Figure 18. Minnesota River Basin General Phosphorus Permit reductions required and achieved

Lake Pepin phosphorus watershed reductions

The Lake Pepin Watershed covers a significant portion of the state and contains 82% of Minnesota

residents. Lake Pepin is impaired due to excess nutrients and, although a TMDL has not yet been

completed, effluent phosphorus limits designed to address the impairment have been incorporated into

permits since 2010.

Phosphorus loads entering the lake have been greatly reduced since the adoption of lake eutrophication

standards in 2008. Increased facility monitoring has also increased the confidence in load values because

most municipal loads are now from observed values. Although aggregate total phosphorus loads from

Minnesota dischargers have reduced effluent loads below the 600 metric ton per year wastewater point


32

source goal for Lake Pepin, the NPDES permit program is in the process of implementing permit limits to

ensure that the load will remain consistent with watershed goals in the future.

Figure 19. Wastewater facilities within the Lake Pepin Watershed

River eutrophication rule and phosphorus discharge limits

Minnesota’s river eutrophication standards (RES) were adopted in 2014 to protect aquatic life from the

negative impacts of excess algae in rivers and streams. RES are applicable in conjunction with lake

eutrophication standards, which were approved in 2008.

In addition to effluent phosphorus limits required for new or expanding discharges and for facilities

whose discharges affect lakes, limits are increasingly being established to meet specific water quality

targets in rivers and streams. Facilities discharging upstream of a waterbody that exceeds river


33

eutrophication standards have greater potential to receive a more restrictive limit upon reissuance.

However, effluent limits associated with lakes are often sufficiently protective for nutrient-impaired

rivers. Limit determinations for individual facilities are based on major watershed scale effluent limit

analyses that consider all wastewater discharges simultaneously. This regional multi-facility approach for

phosphorus limits is also consistent with MPCA’s watershed approach for monitoring, assessment,

protection and restoration.

While limits for many pollutants are based on conditions of the immediate receiving water,

eutrophication limits must consider water quality in a number of downstream waters. The MPCA

outlines the analysis and calculations used to establish necessary phosphorus effluent limits in a

procedure document found at the following link:

https://www.pca.state.mn.us/sites/default/files/wq-wwprm2-15.pdf

The majority of nutrient-impaired streams are in the southern part of the state. There are 50 impaired

reaches totaling 769 miles in length. All streams with nutrient impairments are shown on the map

below, and are also listed on the proposed 2018 nutrient stream impairment list.

Figure 20. Streams with nutrient impairments on the 2018 proposed impairment list

https://www.pca.state.mn.us/sites/default/files/wq-wwprm2-15.pdf


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Total nitrogen

Nitrogen in wastewater generally occurs mostly as either nitrate or ammonia. Nitrogen as ammonia can

be toxic to aquatic life. Nitrogen in the form of nitrate can be a significant problem in drinking water

supplies, and can also be toxic to aquatic life. Recent permits have required more frequent monitoring

for ammonia than for nitrate and/or other nitrogen parameters. As a result, it is difficult to accurately

report the total nitrogen loads (a measure of all forms of nitrogen including nitrate, nitrite, ammonia,

and organic nitrogen) from point source discharges.

Minnesota’s Nutrient Reduction Strategy defines a total nitrogen load reduction goal of 20% from

discharges to the Mississippi River and 13% from discharges to the Red River by 2025. As a first step in

reaching this goal, additional monitoring for the necessary nitrogen parameters will be added to permits

so that a more accurate calculation of the total nitrogen loading from point source discharges can be

established. Once total nitrogen loadings can be accurately defined, initial total nitrogen reductions

efforts will be made through source reduction work.

The 2017 wastewater load for total nitrogen was 15,279 metric tons, a 7% increase from the 2015-2016

average.

Total nitrogen wastewater data are moderately reliable, with only 63% of loads resulting from observed

data points. On average, 91% of wastewater total nitrogen loads are estimated to be discharged by

major facilities. Municipal wastewater dischargers account for 81% of total nitrogen. 2017 wastewater

total nitrogen loads have increased by 17% from the 13,065 metric tons per year from the 2000/2001

baseline load (Figure 21).

Total nitrogen concentrations are not currently collected on a widespread basis and the majority of

observed loads come from very large municipal facilities. Almost all existing total nitrogen wastewater

data are from Metropolitan Council Environmental Services facilities. Increased monitoring by smaller

facilities will provide a more accurate calculation of nitrogen loads in the future.

Figure 21. Total nitrogen loads from wastewater treatment facilities by year



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Total mercury

The wastewater mercury load fell below the Statewide Mercury TMDL wasteload allocation in 2003 and has

continued to decrease slightly since that time. The wastewater mercury load for 2017 was 2.2 kilograms, a

2% increase from the 2015-16 average of 2.3 kilograms. Mercury reduction in wastewater is a result of

successful source reduction programs and installation of treatment technologies for mercury removal,

when appropriate. On average, the data show a 46% reduction in mercury loads from a 4.05 kilogram per

year baseline in 2005/2006.

Total mercury wastewater data are considered moderately reliable with 64% of values resulting from

observed data points. Mercury load estimates prior to 2005 are considered unreliable due to the use of

analytical methods with limited detection capabilities. Analytical laboratories started to provide more

precise mercury detection methods beginning around 2003. Low-level mercury data reported since 2005

is considered to be more reliable.

On average, major wastewater dischargers have accounted for 65% of total mercury loads since 2005.

Municipal wastewater dischargers are estimated to account for 70% since 2005. Overall, wastewater

total mercury loads are estimated to have declined from 4.2 kilograms per year in 2005 to 2.2 kilograms

per year in 2017. In pounds, this translates to about 5 pounds of mercury per year, compared to about

1,500 pounds per year of air emissions.

Figure 22. Total wastewater mercury loads by year

Nonpoint source pollution

Minnesota has made significant progress in cleaning up point sources of water pollution as measured by

discharges of pollutants in municipal and industrial wastewater. It is the nonpoint sources of pollutants--

natural and human-made pollutants carried by rain or snowmelt into lakes, rivers, wetland and

groundwater that now pose the greater challenge and opportunity for prevention and cleanup. Both

point and nonpoint sources of pollution must be controlled to achieve goals set in federal and state law

for protecting human health and the environment.

Over the past few years, more regulatory controls for such sources as feedlots, septic systems and

stormwater have been implemented, but other sources of nonpoint source pollution are diffuse and can

be difficult to assess and manage. Much of the work to control unregulated nonpoint sources of


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pollution thus far has used financial incentives to encourage voluntary adoption of best management

practices. The section below briefly outlines recent projects funded by the Clean Water Land and Legacy

Amendment and estimates associated pollutant reductions. Also highlighted is a new statewide program

that provides incentives for farmers to adopt agricultural best management practices to improve water

quality and recent progress in watershed monitoring and assessment.

Clean Water Fund The Minnesota Legislature appropriated $228.3 million for Fiscal Years 2016-2017 and $201.4 million for

Fiscal Years 2018-2019 to the Clean Water Fund. Project funds are used for water-quality monitoring

and assessment, watershed restoration and protection strategies and drinking water protection

activities.

Minnesota agencies released the most recent Clean Water Fund Performance report in February 2018 to

provide a high-level overview of Minnesota’s investment to restore and protect the quality of the state’s

water resources. The report details how spending and progress are occurring across Minnesota. For a

link to the report and more information on the Clean Water Fund, see the following link:

http://www.legacy.leg.mn/funds/clean-water-fund.

Minnesota Agricultural Water Quality Certification Program The Minnesota Agricultural Water Quality Certification Program is a new statewide voluntary program

designed to expedite the on-farm adoption of agricultural best management practices that protect

water quality. The program is a state and federal partnership. In total, this program has certified over

300,000 acres on 500 farms across Minnesota, adding 900 new conservation practices to the landscape

in approximately two years of statewide operation. Farmers and landowners who implement and

maintain approved farm management practices are certified and in turn obtain regulatory certainty for a

10-year period. Regulatory certainty means certified producers are deemed to be in compliance with

any new water quality rules or laws during the period of certification. These farmers also receive priority

for technical and financial assistance. More information about the Agricultural Water Certification

Program can be found at the following link:

http://www.mda.state.mn.us/protecting/waterprotection/awqcprogram.aspx.

Nonpoint Source BMPs Implemented with Clean Water Funding The Minnesota Board of Water and Soil Resources (BWSR) is the primary state agency responsible for

nonpoint source implementation and works in partnership with local governments. Local

governments—cities, counties, watershed districts and soil and watershed conservation districts—work

directly with individual landowners and communities to implement best management practices that

help reduce polluted runoff from agricultural field and city streets.

BWSR tracks the number of nonpoint source best management practices (BMPs) implemented with

Clean Water funding and the estimated pollutant load reductions associated with these practices. There

is currently no completely reliable way to quantify the volumes of pollutants released by runoff from

nonpoint sources such as city streets, construction sites and farm fields. However, local watershed

managers reporting to statewide data management systems have enabled better estimates of pollutant

loads from nonpoint sources. With funding from the Clean Water Land and Legacy Amendment, the

implementation of practices to improve and protect Minnesota’s water resources has accelerated. The

map on the next page shows the location of state Clean Water Fund projects and the estimated

phosphorus and sediment reductions associated with them. In total, more than 6,872 best management

conservation practices have been installed, resulting in a reduction of about 116,675 pounds of

phosphorus and 121,394 tons of sediment across the state from 2010-2017. While these reductions do

not represent all of best management practices implemented on the land in Minnesota, they

http://www.legacy.leg.mn/funds/clean-water-fund

http://www.mda.state.mn.us/protecting/waterprotection/awqcprogram.aspx


37

demonstrate the improvements resulting from Clean Water Fund investment. Although funding has

increased, and implementation of practices and projects continues to grow, the total request for

projects has remained three times greater than available funds.

Figure 23. Clean Water Fund projects and estimated pollution reductions by major basin, 2010-2017

Progress in watershed monitoring and assessment Clean Water Fund investment is enhancing monitoring of Minnesota’s waters and our understanding of

the relative contributions of pollutants from various sources and waters.

State and local partners began intensive sampling and assessment of lakes and streams in all the major

watersheds in a 10-year cycle, which began in 2008. To date, 93% of major watersheds are completely

monitored and the six final watersheds began monitoring in 2017.

Clean Water Fund investment is improving our understanding of the relative contributions of pollutants

from various sources and waters. One example is the Minnesota Watershed Pollutant Load Monitoring


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Network, which was designed to measure and compare pollutant load information from Minnesota’s

rivers and streams and track water quality trends. This long-term program utilizes state and federal

agencies, universities, and local partners to collect water quality and flow data to calculate pollutant

loads. To learn more about Minnesota’s Watershed Pollutant Load Monitoring Network, see the

following link:

https://www.pca.state.mn.us/water/watershed-pollutant-load-monitoring-network

Contaminants of emerging concern

The MPCA monitors pharmaceuticals, personal care products, industrial, and other wastewater-

associated chemicals in Minnesota's groundwater, lakes, and streams. Although it is not yet possible to

quantify the amounts released to the environment, these efforts are demonstrating the extent to which

these chemicals are found in Minnesota’s surface and groundwater. Most of these chemicals lack

established standards or benchmarks for comparing concentrations and characterizing their risk.

Concern is growing over the potential health effects of these chemicals for humans and the

environment. The work summarized here is often accomplished through collaboration with the USGS,

MDH, the University of Minnesota, St. Cloud State University, and the University of St. Thomas.

Aquatic toxicity profiles Characterizing risks to aquatic life from exposure to these chemicals is complex and difficult in the

absence of formal standards or other benchmarks. Some have endocrine-active characteristics,

mimicking hormones in ways that could adversely affect reproduction, behavior, or physiology in

wildlife, aquatic organisms, and possibly humans. Most of these chemicals have not undergone full

toxicity evaluations.

The MPCA has begun developing Aquatic Toxicity Profiles (ATPs) to provide an overview of chemical-

specific information including chemical properties, occurrence, toxicity, and production volumes. ATPs

can help prioritize chemicals for monitoring and follow-up study.

Lake and river studies Large-scale monitoring of lakes (2012, 2017) and rivers and streams (2010, 2014) shows many

pharmaceuticals, personal care products, detergents, and other commercial or industrial chemicals are

present in most of Minnesota’s surface water. Much of this contamination can be attributed to

wastewater treatment plants (WWTPs), subsurface sewage treatment systems, or agricultural land use.

However, these contaminants often appear at remote locations without apparent sources. The next

large-scale sampling of rivers and streams is planned for 2020.

Groundwater monitoring The MPCA monitors the state’s groundwater annually for the presence of medications, detergents, and

other organic chemicals used in industry or found in personal care or household products. The agency

tests 40 wells in its ambient groundwater network each year for these types of chemicals. This work has

found low levels of a variety of these chemicals in the state’s groundwater.

Precipitation study A 2016 study found antibiotics, anti-corrosives, bisphenol A, DEET, and other chemicals in samples of

snow, rain, and air. While the study did not determine the source of these contaminants to the

atmosphere, the results suggest that atmospheric transport of these contaminants may partially explain

their appearance at remote surface water locations in Minnesota.

https://www.pca.state.mn.us/water/watershed-pollutant-load-monitoring-network


39

Fish studies A 2014 screening study indicated that chlorinated paraffins (CPs) may be present at concentrations of

concern in Minnesota fish. CPs are widely used in a variety of products, including fire retardants,

plastics, sealants, adhesives, and coatings. In 2015, over 350 fish representing a variety of species were

collected from 43 waters (13 rivers, 30 lakes) in six of Minnesota’s seven ecoregions. Short-, medium-

and long-chain CPs were detected in fish fillets from 62% of rivers and 27% of lakes.

Groundwater at wastewater land application sites In 2016, The MPCA and USGS completed a groundwater contaminant study of large drainfields,

municipal rapid infiltration basins and a septage land application site. A total of 34 different

contaminants were detected in the shallow groundwater adjacent to these systems, including

pharmaceuticals, flame-retardants, corrosion inhibitors, fragrances, and pesticides. No individual

contaminant exceeded a concentration of 1 part per billion, nor did they exceed available drinking water

guidelines, screening values or standards. However, most of the chemicals lack established standards or

benchmarks for comparing concentrations and characterizing their risks.

Stormwater In 2016, stormwater was tested at nine locations in the Twin Cities Metro Area for a broad suite of

pharmaceuticals and other wastewater-associated chemicals. The results of this investigation show that

stormwater is an important contributor of these contaminants to surface water, and that treatment of

stormwater can reduce contaminant concentrations.

Other special studies A study of 25 WWTPs in 2009 confirmed that wastewater effluent is a major contributor of

pharmaceuticals, alkylphenols, and other chemicals to surface water, highlighting the fact that WWTPs

are not designed to remove such chemicals from wastewater. Focused lake studies from 2008 through

2013 demonstrated the widespread presence of these chemicals in both urban and rural lake water.

Biological effect studies, done in conjunction with MPCA’s sampling investigations, consistently indicate

physiologic and genetic impacts on fish exposed to surface water with low concentrations of these

chemicals. https://www.pca.state.mn.us/water/pollutants-emerging-concern.

PFAS Poly- and perfluoroalkyl substances (PFAS, also known as PFCs) are manmade chemicals used to

manufacture products that are heat- and-stain resistant and repel water. PFAS used in emulsifier and

surfactant applications are found in fabric, carpet and food-paper coatings, coatings for smartphone and

computer screens, floor polish, waxes, cosmetics and hair care, dental floss, fire-fighting foam,

compostable food ware, adhesives, and certain insecticides. PFAS are persistent in the environment and

known to bioaccumulate in humans and biota. In general, greater PFAS chain length results in longer

half-lives and greater potential toxicity in humans. PFAS have been found in animals and people all over

the globe.

In Minnesota, 3M manufactured perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)

from approximately 1950 until they were phased out in 2002. During that time, large volumes of PFAS

were released into the Mississippi River in effluent from the 3M Cottage Grove wastewater treatment

plant. In addition, four sites in Washington County were identified where 3M disposed of PFAS wastes.

These are in Oakdale, Woodbury and Cottage Grove, and at the former Washington County Landfill in

Lake Elmo, and have resulted in a 100-square-mile plume of PFC-contaminated groundwater.

MPCA investigations also detected PFOS at elevated concentrations in fish taken from Pool 2 of the

Mississippi River and downstream, as well as in east metro area lakes. In addition, PFOS has also been

found in fish from other metro area lakes, most with no known connection to 3M’s manufacturing or

https://www.pca.state.mn.us/water/pollutants-emerging-concern


40

waste disposal. Mississippi River Pool 2, which received 3M Cottage Grove effluent during the years of

PFOS and PFOA manufacturing, is listed as impaired due to PFOS. Follow-up testing of fish and water has

shown an overall decline in Pool 2 PFOS concentrations in fish, with elevated levels remaining in the

lowest reach of the pool near the 3M Cottage Grove plant.

See 2012 report on fish, water, sediment, and invertebrate sampling at

http://www.pca.state.mn.us/index.php/view-document.html?gid=19516

Although PFOS and PFOA have been phased out, there are an estimated 3,000 – 5,000 other PFASs in

production. PFAS can enter the environment during manufacture, distribution, use, and disposal of

products. In addition to fish tissue, PFAS have been found:

In shallow groundwater wells

In the influent, effluent and biosolids of wastewater treatment plants

In ambient air

In blood of bald eagles

In tree swallows

In household dust

In landfill leachate and gas

Several findings of elevated PFOS concentrations have been traced to chrome-platers using PFOS-

containing products in plating or for chrome mist suppression.

Most occurrence and toxicity studies have focused on PFOS and PFOA, two PFAS which have been

phased out of production. However, many other PFAS continue to be produced and used in high

volumes; some of these PFAS can breakdown to PFOS or PFOA, resulting in continued environmental

contamination.

In May 2016, the EPA announced the results of a multi-year review of its health-based guidance for

drinking water exposure to PFOS and PFOA, and lowered its health benchmark from 300 nanograms per

liter (ng/l) to 70 ng/L. In May 2017, the MDH tightened its health-based guidance for PFOS and PFOA

even further, down to 27 ng/L and 35 ng/L respectively. More information on health risks is at this link:

http://www.health.state.mn.us/divs/eh/hazardous/topics/pfcshealth.html

In addition, emerging evidence indicates widespread environmental contamination by other PFAS. For

example, GenX is a new PFAS produced to replace PFOA in nonstick cookware that has shown to be

persistent and bioaccumulative. Limited toxicity studies indicate GenX may be linked to pancreas, liver,

and testicular cancer. GenX is just one example of a newly discovered PFAS. The environmental

presence and potential human health and ecotoxicological effects of emerging PFAS are unknown.

These growing concerns have led an international group of PFAS researchers to propose restrictions on

production and use of fluorinated chemicals and promote development of non-fluorinated

alternatives. The “Madrid Statement” of 230+ signatory scientists is provided at this

link: https://ehp.niehs.nih.gov/wp-content/uploads/123/5/ehp.1509934.alt.pdf

A counterpoint from the FluoroCouncil, an American Chemistry Council affiliate representing

fluorochemical manufacturers, can be viewed at:

https://fluorocouncil.com/PDFs/The-FluoroCouncil-Counterpoint-to-the-Madrid-Statement.pdf

http://www.pca.state.mn.us/index.php/view-document.html?gid=19516

http://www.health.state.mn.us/divs/eh/hazardous/topics/pfcshealth.html

https://ehp.niehs.nih.gov/wp-content/uploads/123/5/ehp.1509934.alt.pdf

https://fluorocouncil.com/PDFs/The-FluoroCouncil-Counterpoint-to-the-Madrid-Statement.pdf

Documents

2018 Pollution Report to the LegislatureThis report is available in alternative formats upon request, and online at . Document number: lrp-ear-2sy18 Legislative charge Minn. Statutes